cut flower of the month

calla

BOTANICAL NAME

Zantedeschia spp. (zan-te-DES-kee-uh)

COMMON NAMES

Calla and miniature calla (U.S.)
• Arum lily (primarily in the United Kingdom and Europe)
• Pig lily (in their native South Africa, where they’re common roadside plants)
• Trumpet lily (a reminder of the archangel Gabriel and his trumpet)

(For more information, see “Fun Facts: Mistaken Monikers,”)

DESCRIPTION

Calla inflorescences consist of funnel-shaped and recurved spathes (actually colored petal-like leaves) that surround fleshy fingerlike spikes, called spadices (singular: spadix). Stems are smooth and leafless.

Standard calla (Z. aethiopica) inflorescences vary from 5 to 10 inches in length, and stem lengths usually range from about 20 to 36 inches although they can grow as long as 48 inches. Miniature calla (New Zealand hybrids) inflorescences vary from about 3 to 5 inches, and stem lengths generally range from about 8 to 20 inches, but they can grow to 32 inches in length.

COLORS

Most varieties of standard callas are classic white or ivory, but there are some bicolor varieties, including the bold green-and-white ‘Green Goddess’ and the blushing lavender/pink-and-white ‘Diva Maria’.

Miniature callas’ hues include white, lavender, purple, pink, “red,” orange, bronze, rust, yellow, “brown” (deep brownish burgundy), “black” (deep reddish purple) and bicolors. These blooms tend to color differently under various growing conditions, so think in terms of a color range when ordering.

VASE LIFE

With proper care from farm to consumer, both standard and miniature callas should last from four to eight days in customers’ homes, offices, etc.

AVAILABILITY

Both standard and miniature callas are available year-round, with peaks from spring through fall.

Vase-life extenders

PREPARATION

Unpack callas immediately upon their arrival at your facility. Handle these delicate flowers carefully to avoid bruising the blooms and damaging the fleshy stems.

HYDRATION AND NUTRITION

Cut at least 1 inch from the bottoms of the stems, on an angle—avoid removing all of the white stem end, if possible—and place the flowers immediately into a clean container partially filled with properly mixed flower-food solution. Callas do not benefit from the nutrient (sugar) in flower-food solutions, but they do benefit from the biocide, which controls the growth of stem-plugging microbes in the water. Leaving part of the white stem ends intact helps with water uptake and vase life while reducing the chances of stem splitting or curling (see “Care Extras”).

REFRIGERATION

Place processed callas immediately into a floral cooler, and allow them to hydrate for at least two hours before selling or arranging them. Store white varieties at 36 F to 38 F and colored cultivars at 43 F to 46 F; lower temperatures can cause chill damage. Also, do not store these flowers longer than three days.

ETHYLENE SENSITIVITY

Callas are not ethylene sensitive, and contrary to popular belief, they do not produce significant quantities of ethylene.
care extras Callas’ stem ends will often split and curl. To minimize this, wrap the stems near their ends with waterproof tape, and don’t cut off all of the white portion at the end of the stems.

Callas that are shipped dry may arrive a little limp, but they will revive after being recut and hydrated. Stems can be straightened by wrapping them (but not the blooms) loosely in newspaper and storing them upright in a tall bucket or vase.

fun facts
WHAT'S IN A NAME Some histories suggest that the genus name Zantedeschia was given in honor of Francesco Zantedeschi (1797-1873), an Italian botanist, priest, physicist and professor. Other records say the genus was named after Giovanni Zantedeschi (1773-1846), an Italian botanist and physician. The word “calla” is Greek for beautiful. FAMILY MATTERS Callas are members of the Araceae (arum) family. Relatives include Anthurium, Caladium, Dieffenbachia, Spathiphyllum, Chinese evergreen (Aglaonema), arrowhead (Syngonium/Nephthytis), elephant’s ear (Alocasia) and jack-in-the-pulpit (Arisaema). HOME SWEET HOME Callas are native to South Africa. MISTAKEN MONIKERS Although often called “calla lilies,” these flowers (Zantedeschia genus in the Araceae family) are not related to lilies (Lilium genus in the Liliaceae family). The Zantedeschia genus also is different from the genus Calla, a perennial that grows in boggy areas and is commonly known as water arum, bog arum, wild calla or water-dragon.
toxicity alert
Sap in calla stems contains oxalic acid crystals, which may cause skin irritation in some people as well as tongue swelling, if ingested.
purchasing advice
• Buy cut callas at the stage of openness desired for sale or use. If cut too tight, these flowers may not open properly, if at all. • Don’t purchase callas too early; buy them close to the time they are needed. • Blooms should be free of spots, blemishes or splits, and the stems should not be soft or slimy.

To view the 18 Miniature Calla (New Zealand Hybrids) varieties, please download the pdf.
(printable PDF)
If you have trouble viewing these PDF (portable document format) files, download a copy of the free Adobe Reader.

Photos: ‘Hot Chocolate’ from Esmeralda Farms; all others from CallaCo, a division of Golden State Bulb Growers

Some information provided by:

Botanica, by R.G. Turner Jr. and Ernie Wasson
Chain of Life Network® , www.chainoflife.org
Cut Flowers of the World by Johannes Maree and Ben-Erik van Wyk
Hortus Third by Liberty Hyde Bailey and Ethel Zoe Bailey
SAF Flower & Plant Care by Terril A. Nell, Ph.D. and Michael S. Reid, Ph.D.
Stearn’s Dictionary of Plant Names for Gardeners by William T. Stearn